Manufacture of threads, filaments, strips, or films of cellulose.



. To all whom it may concern:

atman srn rnis rerun onnrc.

SIDNEY SCRIVENER NAPPER, OF COVENTRY, ENGLAND, ASSIGNOR T0 SAMUELCOURTAULJD & COMPANY LIMITED, 01 LONDON, ENGLAND.

MANIIFAGTURE 0F THREADS, FILAMENTS, STRIPS, 0R FILMS 0F CELLULOSE.

No Drawing.

Be it known that I, SIDNEY ScRIvENER NAPPER, a subject of the King ofGreat Britain and Ireland, of 7 Ellys road, Coventry,

in the county of Warwick, England, have invented new and usefulImprovements in i Connection with the Manufacture of Threads,

Filaments, Strips, or Films of Cellulose, of which the following isaspecification. p The regeneration of cellulose hydrate in the form ofthreads, filaments, strips, or films, from viscose, has been, effectedby forcing a suitable viscose 'through orifices, or apertures, intoso-called setting baths, two different classes of. which baths have beenused for the purpose-namely, class 1, a

bath such as an aqueous solution of ammonium sulfate, in which theviscose is precipitated as xanthate; class 2, a bath in which cellulosehydrate is regenerated from viscose by the action of the bath. A numberof baths of this class 2, of difi'erent compositions, have beenemployed; Such baths may consist for example of dilute sulfuric acidalone, or with additional ingredients, for instance, (severally orjointly) salts of sulfuric acid, glucose, and the like.

The present invention consists in an improvement of the baths belongingto theaforesaid class 2 and results in superior products and in economyin working. The improvement consists in adding to a bath, such as thosehereinbefore classified under 2, a small quantity of zinc salt,preferably "zinc sulfate, or of zinc, or a zinc compound,

which, by the action of the acid in the bath,

will be c0nverted into a zinc salt, and in the, 'use of such a bath fortheregeneration of cellulose hydrate from viscose.

The lowing are examples of ways in which t new bath may be prepared, butI Specification of Letters Patent.

do not limit myself to the precise details of these examples. The partsare by weight.

Example: sulfuric acid, 81} parts; glu- 'cose, 9 parts; ammoniumsulfate, 4 parts;

sodium sulfate, 12 parts; zinc sulfate, 1

part 5 .water, 65 parts.

Example 2: sulfuric acid, 8 parts; glucose, 10 parts; sodium sulfate, 12parts; zinc sulfate, 1 part; water, 69 parts.

The proceedings for effecting the regeneration of cellulose hydrate fromviscose by means of such a bath can be conducted in the usual well knownway.

Although I have found that the quantity Patented Nov. 26, 1912.

Application filed September 25, 1911 Serial No. 651,249.

of zinc salt mentioned in the examples gives good results, I, asaforesaid, do not limit myself thereto, but I have found that thequantity of zinc salt added to, or formed in, the bath should not amountto much more than about'three per cent. of the weight of the bath.

What I claim is:

1. In the production of cellulose objects from viscose, the introductionof the latter in suitable form into an acid setting bath in the presenceof a zinc salt in quantity not materially exceeding three per cent. byweight of the bath.

2. In the production of. cellulose ojectsfrom viscose, the introductionof the atter in suitable form into an acid setting bath containing azinc salt 1n quantity not materially exceeding three per cent. by weightof the bath.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses. Y

SIDNEY SCRI-VENER NAPPER. Witnesses: LEONARD P. WILSON,

FRANK SHEDDEN.

